The increased terminal mobility offered by cellular telephone networks as well as mobile and WiFi radio data networks has brought about an increased demand for location-based services and applications. Location based services include, for example, fleet management, vehicle tracking, tracking for theft recovery, telemetry, emergency services, location identification, navigation, location based information services and location based advertising. A wide variety of technologies for locating mobile devices have been developed.
Typical mobile device location technologies may be classified into external methods and network based methods. One example of an external method is the Global Positioning System (“GPS”). Network based methods may be further categorized depending on whether it is the network or the mobile device that performs necessary signal measurements. These signal measurements may involve the reception time of signals communicated between a base station and a mobile device, the angle of arriving signals or round trip delay measurements of signals communicated between a serving base station and a mobile device, or combinations thereof.
However, for many current and future location based applications, accuracy of the calculated position information should be improved.